﻿//2011-7-25 zhangying
(function () {
    function load_script(xyUrl, callback) {
        var head = document.getElementsByTagName('head')[0];
        var script = document.createElement('script');
        script.type = 'text/javascript';
        script.src = xyUrl;
        //借鉴了jQuery的script跨域方法
        script.onload = script.onreadystatechange = function () {
            if ((!this.readyState || this.readyState === "loaded" || this.readyState === "complete")) {
                callback && callback();
                // Handle memory leak in IE
                script.onload = script.onreadystatechange = null;
                if (head && script.parentNode) {
                    head.removeChild(script);
                }
            }
        };
        // Use insertBefore instead of appendChild  to circumvent an IE6 bug.
        head.insertBefore(script, head.firstChild);
    }
    function transMore(points, type, callback) {
        var xyUrl = "http://api.map.baidu.com/ag/coord/convert?from=" + type + "&to=4&mode=1";
        var xs = [];
        var ys = [];
        var maxCnt = 20;//每次发送的最大个数
        var send = function () {
            
            var url = xyUrl + "&x=" + xs.join(",") + "&y=" + ys.join(",") + "&callback=callback";
            //动态创建script标签
            load_script(url);
            xs = [];
            ys = [];
        }
        for (var index in points) {
            if (index % maxCnt == 0 && index != 0) {
                send();
            }
            xs.push(points[index].lng);
            ys.push(points[index].lat);
            if (index == points.length - 1) {
                send();
            }
        }

    }

    window.BMap = window.BMap || {};
    BMap.Convertor = {};
    BMap.Convertor.transMore = transMore;
})();